Compatibility problem with samsung DVD-611

I am doing research on buying a DVD burner, but along the way I found compatiblity lists for DVD+/-r and the Samsung DVD-611 is listed as compatible with both media.

The problem is that none of my backups (+ or -) work with this player. I am currently forced to use my ps2 for playing my backups, but I would rather use the dvd player. Can someone please tell me what is making the backups incompatible?

Thanks in advance.

P.S. I am also having the same problem, with a Toshiba player, but that claims only compatibility with - media.

update the firmware on your current dvd burner
use quailty media, and a quailty burning program to burn the dvds
booktype any +R/RW you use to DVD-ROM